The housings for traditional outdoor luminaires are typically made from aluminum by a die casting process. The die casting process can have high material and tooling costs. Outdoor luminaires with light emitting diode (LED) light sources usually have the LED light sources located on a printed circuit board (PCB) located within the die cast housing.
The PCB to which the LED light sources are mounted is typically smaller than the interior of the housing, which places individual LED light sources in close proximity to one another. The density of this LED light source arrangement requires the use of high thermal conductivity material (copper, aluminum, etc.) as a heat sink to draw heat away from the PCB and the LED light sources. A thermal interface material, for example grease, could be applied between the PCB and the heat sink to improve thermal contact. These traditional LED outdoor luminaires often have an optical unit (e.g., lens, reflector, shield, cover, etc.) located over the multiple LED light sources of the luminaire.
Conventional LED luminaires having plastic housings typically are not produced for outdoor luminaire applications. Some LED luminaires with plastic housings are made with a thermally conductive plastic, or use a heat sink located between the LED light source PCB and the housing so that the PCB is not in direct thermal contact with the plastic housing.